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growing bacteria in agar
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Growing Bacteria in Agar

In this activity, we will swab surfaces and record what we observe while growing bacteria in agar.
Prep Time30 minutes
Active Time5 days

Equipment

  • 1 Agar testing kit

Materials

  • 1 kit Agar testing kit
  • 1 piece permanent marker
  • 1 copy lesson printout
  • 1 pair safety glasses
  • 1 pair disposable gloves

Instructions

  • Determine where you will place the petri dishes while you wait for the colonies to grow. Try to place in a warm area between 78 degrees Fahrenheit and 100 degrees Fahrenheit. A warm room or incubator works well.
  • Identify what you want to sample.
  • Fill out the lab worksheets to label what is being tested.
  • Wash hands, put on gloves, and put on eye protection.
  • You will use one swab per surface swabbed.
  • Run the swab over the first item or area you want to swab. Twirl the swab as you wipe to get material all over the cotton tip.
  • Remove the lid from one agar plate.
  • Gently roll the swab over the agar material. Do not press down too hard. Just run the swab over the agar.
  • Place the cover back onto the agar plate.
  • Dispose of the swab.
  • Flip the agar dish over and write down the date, time, and what was swabbed. KEEP THE PETRI DISHES COVERED AND UPSIDE DOWN. Condensation may form on the inside tops of the dishes, and we do not want the condensation dripping down on the agar.
  • Fill out the activity worksheets in the lesson printable.
  • Place the petri dishes in a warm place. All of the dishes should receive the same temperature and light. The ideal temperature is between 78- and 100-degrees Fahrenheit. Do not open the dishes!
  • Observe the petri dishes for 3 to 5 days and record your results.
    growing bacteria in agar
  • Once the activity is complete, wear gloves and eye protection and dispose of the dishes properly. Do not open the lids. Toss all gloves and disinfect the area where the dishes were sitting.